Toner cleaning apparatus

ABSTRACT

Apparatus for separating residual toner particles from a moving photoconductive surface and for automatically storing the separated particles within a storage area. A blade element is arranged to move between the photoconductive surface and the residual toner material to separate the toner from the surface and direct the toner into contact with a transport roll. The transport roll moves the toner away from the cleaning zone and into a collecting zone. A paddle is rotatably supported to pump the toner into a substantially horizontally aligned storage area. Further means are provided to clean the paddle as it passes through the storage area and to seal the storage area to prevent the separated residual toner from migrating back into the cleaning zone.

United States Patent 1191 Oriel TONER CLEANING APPARATUS I [75]Inventor: George J. Oriel, Fairport, NY.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

22 Filed: May 23,1973

211 App]. No.: 362,979

Related US. Application Data [62] Division of Ser. No. 184,156, Sept.27, 1971.

[52] US. Cl. l5/256.5l, 355/15 [51] Int. Cl G03g 13/08, B08b 1/02 [58]Field of Search 15/256.51, 256.5, 1.5,

1451 Oct. 1, 1974 3,660,863 5/1972 Gerbasi l5/256.5l

Primary ExaminerLeon G. Machlin Attorney, Agent, or Firm-James J.Ralabate; Paul Weinstein; Clarence A. Green 5 7 ABSTRACT Apparatus forseparating residual toner particles from a moving photoconductivesurface and for automatically storing the separated particles within astorage area. A blade element is arranged to move between thephotoconductive surface and the residual toner material to separate thetoner from the surface and direct the toner into contact with atransport roll. The transport roll moves the toner away from thecleaning zone and into a collecting zone. A paddle is rotatablysupported to pump the toner into a substantially horizontally alignedstorage area. Further means are provided to clean the paddle as itpasses through the storage area and to seal the storage area topreventthe separated residual toner from migrating back into the cleaning zone.

12 Claims, 5 Drawing Figures TONER CLEANING APPARATUS This applicationis a division of US. Application, Ser. No. 184,156, filed Sept. 27,1971.

This invention relates to the cleaning of residual toner material fromthe surface of a reusable image retaining plate and, in particular, toapparatus for automatically handling and storing residual toner materialcleaned from the surface of a reusable xerographic plate.

Conventionally, in the automatic xerographic process, a latentelectrostatic image of an original to be reproduced is recorded upon animage retaining member and the image then made visible, or developed, bymeans of a finely divided particulate toner material which has beenspecifically developed for this purpose. In reusable xerography, thedeveloped toner image is generally transferred from the xerographicplate to a final support material, such as paper or the like, and theimage affixed thereto to form a permanent record of the original inputscene information. Although a preponderence of the toner materialcomprising the developed image is transferred to the final supportsheet, a small amount of residual toner nevertheless invariably remainsbehind on the plate surface after the transfer operation. In order torestore the plate to a condition suitable for reuse, this vestige oftoner must be cleaned or removed from the plate surface before a newimaging cycle is instituted.

The cleaning of the xerographic plate may be accomplished in a number ofdifferent ways. One prevalent technique is to separate the residualtoner from the plate by means of an elastomeric blade element asdisclosed in copending application Ser. No. 838,984 to Gerbasi. In theblade cleaning process, the cutting edge of the blade is arranged tomove between the residual toner particles and the image bearing platesurface to chisel or cut the toner particles therefrom.

The trend in automatic xerographic apparatus has been to smallermachines capable of producing copy of a relatively rapid rate, as forexample, in high speed desk top duplicators. This trend towards smallerbut yet faster devices has placed an extremely heavy burden upon themachines cleaning systems in that they must now handle and store withinan extremely restricted area an ever increasing amount of residual tonermaterial.

It is therefore an object of this invention to improve xerographiccleaning.

It is the further object of this invention to improve apparatus forhandling and storing residual toner material as it is cleaned from thesurface of an image bearing plate.

It is yet another object of this invention to provide apparatus capableof storing a maximum amount of residual toner material in a minimumamount of machine space.

These and other objects of the present invention are attained by meansof a cleaning device comprised of at least one doctor blade elementadapted to separate residual toner particles from a moving imagerecording plate, means to collect the separated toner particles and totransport the particles away from the cleaning zone into a collectingarea, and a mechanical impeller within the collecting area which isarranged to pump the collected toner into a restricted storage region.

For a better understanding of the present invention as well as otherobjects and further features thereof, reference is had to the followingdetailed description of the invention to be read in conjunction with theaccompanying drawings wherein:

FIG. l is a schematic view of an automatic xerographic reproducingmachine incorporating the improved cleaning apparatus embodying theteaching of the present invention;

FIG. 2 is a perspective view partially broken away showing the tonerhandling and storing mechanism associated with the cleaning apparatusillustrated in FIG.

FIGS. 3-5 are partial end views of the impeller for pumping separatedresidual toner material into the storage area of the cleaning deviceshown in FIG. 1 illustrating the step of cleaning the impeller andsealing the storage'region.

Referring to the drawings, there is shown, for the purpose ofexplanation, an automatic xerographic reproducing machine incorporatingthe improved doctor blade cleaning apparatus of the present invention.The copying machine employs a drum like member 10, the outer peripheryof which is furnished with a suitable xerographic imaging orphotoconductive layer 11 which is well known to those skilled in theart. Drum 10, which is suitably journaled for rotation in the machine bymeans of a shaft 13, rotates in the direction indicated in FIG. l tobring the image retaining surface 11 thereon past a plurality ofxerographic processing stations. Suitable drive means (not shown) areprovided to power and coordinate the motion of the various machineoperating components whereby a faithful reproduction of the originalinput scene information is xerographically created.

Since the practice of xerography is well known in the art, the variousprocessing station for producing a copy of an original are herein shownin block diagram form and are referred to as stations A through E. Atstation A, a uniform charge is placed upon the photoconductive surfaceof the drum member. The charged drum is then moved past an exposurestation E for illuminating the charge surface with a light image of theoriginal input scene information so that the charge isselectivelydissipated in the light struck regions to record the original inputscene information on the photoconductor in the form of a latentelectrostatic image. Means for applying toner material to the imagebearing surface is provided at station C whereby the latent image isrendered visible. The developed image is then brought into contact witha final support sheet at transfer station D and the toner imagetransferred from the xerographic drum surface to the support sheet.Finally, at station E, an improved doctor blade cleaning apparatus,embodying the teachings of the present invention, acts to remove anyresidual toner material that might remain on the drum surface after thetransfer operation and from the surface thereof and automatically storesthe toner within a cleaning housing in a manner to be explained ingreater detail below.

The cleaning station E includes a relatively flexible blade member 20.The blade is movably supported within the cleaning housing 21 so that itcan be incrementally stepped back and forth across the drum surface ltlalong a predetermined path of travel with the cutting edge 22 of theblade running in contact with the drum surface. Preferably, the workingsurface, or cutting edge of the blade should be equal to the width ofthe photoconductive layer supported on the drum surface plus the totalamount that the blade is extended as itreciprocates back. and forth overits path of travel. The blade is also preferably positioned with thecutting edge extended toward the drum in a direction substantiallyopposed to the direction of drum motion so that the blades cutting edgemoves between the residual toner particles and the photoconductive drumsurface to effect the desired cleaning. The relative blade anglesbetween the blade surfaces and a plane tangent to the line of contactbetween the blade edge 22 and the drum surface 11 is selected so as toproduce optimum cleanmg.

Blade 20 is comprised of any suitable flexible material such aspolyurethane or the like. Preferably, the elastomeric blade materialemployed should be relativelysgft to prevent or minimize surfaceabrasion, scratching, etc. of the photoconductive plate, however, thematerial should possess sufficient strength and resiliency to alloweffective cleaning.

As illustrated in FIG. 1, the blade element is located above thehorizontal center line of drum with the cutting edge thereon extendingdownwardly in opposition to the upward movement to the photoconductivesurface. As a consequence, the residual toner particles moving over thecutting edge 22 of the blade are caused to fall downwardly towards thebottom of the cleaning housing. A cylindrical sealing roll 25, which isaligned parallel to the xerographic drum 10, is located below the bladeelement in a position to intercept the falling toner particles. The rollis rotatably supported between the side walls of the cleaning housingand has an outer blanket 25 thereon constructed of a relatively softresilient material which is arranged to ride in light biasing contactwith the xerographic drum surface. The blanket is preferably constructedof an elastomeric material, such as Neoprene or the like, having ahardness of between 50 and 60 durometers capable of providing a positiveseal against the drum surface. The length of the cylindrical roll is atleast equal to that of the xerographic drum and seals the entire lowerportion of the cleaning region thereby preventing the separated tonerparticles from escaping form the cleaning housing and thus precludingthe toner from being broadcast through the interior of the automaticmachine.

A pair of cooperating gear members 27, 28 (FIG. 2) are provided throughwhich the motion of the sealing roll is coordinated with that of thexerographic drum 10 so that the two contacting surfaces move at the samerelative speeds. As the gear mechanism turns the sealing roll in thedirection indicated, the particulate toner material that has fallen intocontact therewith is transported away from the photoconductive surfaceand out from the cleaning zone. A scraper bar 30 rides in light pressurecontact with the surface of sealing roll and is arranged to separate theresidual toner particles from the surface of the roll. In operation, theresidual toner particles are driven over the back side of the scraperbar and fall into a collecting region 34 located in the bottom of thehousing. A square shaped impeller or block paddle 32, extendinghorizontally across the cleaning housing is rotatably supported betweenthe housing sidewalls and is arranged to rotate in an endless path oftravel through the collecting area. Although the paddle can beconstructed of any suitable material, it is preferred that it be made ofa plastic material exhibiting good release properties in relation to thetoner materials. Although not shown, a side seal can be providcd betweenthe ends of the paddle and the sidewalls of the housing to prevent tonerparticles from moving therebetween.

In practice, the square paddle serves as a means for moving toner out ofthe collecting area into the horizontally aligned storage area 35 of thecleaning housing. As illustrated in FIG. 2, a drive pinion 74 is securedto the sealing roll shaft 75 and meshes with a gear member 76operatively connected to the paddle drive shaft 77. The movement of thepaddle wheel is coordinated through the gear system so that the paddleis moved at a speed sufficient to handle and pump rearwardly the tonerthat is delivered into the collecting area by the sealing roll.

A flexible wall 36 is supported in the top wall of the cleaning housingand extends downwardly in a substantially vertical direction so as toride in contact with the extended sides of the square paddle. Theflexible wall is preferably fabricated of a relatively thin strip ofMylar which extends across the interior of the housing and provides amovable wall capable of retaining the residual toner within the storagearea. Although the paddle is constructed of a relatively abhesivematerial, the toner particles will, under certain conditions, becomeimpacted and coalesce upon the blade, that is, the edges formed by theabutment of the rectangular blade sidewalls, as the material is beingpumped into the storage area. The flexible wall member is arranged toalso function as a cleaning expedient for removing this impacted tonerfrom the paddle blade types prior to their passing out of the storagearea.

As shown in FIGS. 3-5, the flexible wall 36 initially rides downelongated sidewall (a) of the paddle as the sidewall is moved in anupward direction (FIG. 3). As the sidewall continues to move upwardlytowards a horizontal position, the flexible wall is carried over the tip91 of the paddle and flicks the impacted toner material back into thestorage area (FIG. 4). Eventually, the next subsequent sidewall 90 (b)of the paddle block moves into a vertical position into substantiallyparallel alignment with the flexible blade member as illustrated in FIG.5. Continued rotation of the paddle brings the next tip 92 into aposition to be cleaned.

Because of its unique design, the square paddle and flexible wallarrangement cooperates to provide a relatively simple and effectivemeans for pumping large amounts of residual toner into a relativelyrestricted area. As can be seen, the wall is adapted to form a flexibleseal capable of preventing toner from being carried over the top of thepaddle and as a result enables the entire storage area of the house tobe filled to capacity.

To enhance the cleaning efficiency of the doctor blade and to avoid, orat least considerably reduce, localized wear on the blades cutting edgeas well as substantially eliminating entrapment of foreign matterbetween the blade and the drum surface, the doctor blade is periodicallystepped in predetermined increments back and forth across the drumsurface 11 over a path of travel substantially normal to the directionof motion of the drum.

Referring more specifically to FIG. 2, the blade element is supportedwithin a U-shaped mounting bracket 40 and the bracket suspended from asupport bar 42 by means of centrally located pivot pin 44. As can beseen,

the blade is free to swing about the pivot in a horizontal direction andcan align itself along the width of the drum surface. The support barhas rigidly affixed thereto a pair of hinges 46 which are both slidablyand rotatably supported upon a hinge pin 47 anchored in the sidewalls ofthe housing. The blade support assembly is offset from the hinge pin andtends to rotate thereabout in a counter clockwise direction as seen inFIG. 1. This, in turn, mechanically biases the flexible blade intopressure contact with the drum surface with sufficient force to insurethat a continuous unbroken line of contact is maintained between thecutting edge of the blade and the photoconductive surface being cleaned.

In order to step the blade incrementally back and forth along itslongitudinal path of travel, there is provided a drive mechanism,generally referenced 50 (FIG. 2) acting in concert with a movablecarriage 52. The drive mechanism includes a ratchet '55, rotatablysupported upon one end of tie rod 56 and being arranged to turn acylindrical cam element 57 secured thereto. Carriage 52 is slidablymounted upon the tie bar and is continually urged towards the camelement by means of a spring member 59 whereby cam follower 60, securedto the carriage, rides in contact with the contoured working face of thecam. Extended arm 61, of the carriage, is provided with a slottedaperture 62 that operatively engages the raised portion of the righthand hinge 46. The prescribed cam motion is thus translated through themovable carriage and the blade support assembly causing the blade tomove longitudinally back and forth across the drum surface overapredetermined path of travel. Preferably the cam is adapted so as totranslate a simple harmonic motion to the blade element.

A speed control unit made up of pawl 70, which operatively engagesratchet 55, and a speed reducing gear 71 are secured to the paddle blockshaft 73. The reducing gear meshes with a drive pinion 74 which isdriven by the sealing roll drive shaft 75. The pawl is eccentricallymounted upon its supporting shaft so that'the tip of pawl arm 77, whichis adapted to engage the teeth of ratchet 55, advances the ratchet apredetermined distance for each revolution of the shaft. A lockingmechanism 80 also is arranged to ride in engagement with the ratchetteeth and prevents the ratchet from slipping backwardly in a counterclockwise direction as the pawl armis pulled back preparatory to thenext subsequent advancing stroke. The ratchet arrangement together withthe reduction gear 71 are chosed to periodically turn the cam elementrelative to the drum speed thereby incrementally repositioning the bladeelement in a manner wherein the blade moves back and forth over a pathof travel parallel to the drum surface.

While this invention has been described with reference to the structuredisclosed herein, it is not confined to the details set forth, and thisapplication is intended to cover any modifications or changes as maycome within the scope of the following claims.

What is claimed is:

1. An apparatus for separating residual toner material from the surfaceof a reusable image retaining member preparatory to recycling saidmember, comprising:

a cleaning element arranged to operatively communicate with said imageretaining member to 3555 rate residual toner images from the surfacethereof; and

sealing means positioned below said cleaning element for interceptingthe falling toner particles and transporting said particles away fromsaid reusable image retaining member, said sealing means including amoving surface which is arranged to ride in contact with said reusableimage retaining memher.

2. An apparatus as in claim 1 wherein said sealing means comprises aroll mounted for rotation.

3. An apparatus as in claim 2 wherein, said roll has an outer blanketthereon constructed of a resilient material.

4. An apparatus as in claim 3 wherein, said resilient material comprisesneoprene.

5. An apparatus as in claim 3 whereimsaid resilient material has ahardness of between about 50 and 60 duronieters.

6. An apparatus as in claim 3 further including a scraper bar adapted toride in contact with the outer surface of said sealing roll and arrangedto separate said toner particles from said surface of said roll.

7. An apparatus as in claim 6 wherein, said reusable image retainingmember comprises a xerographic drum.

8. An apparatus as in claim 7 wherein, the contacting surface of saiddrum and said roll move at the same relative speeds.

9. An apparatus as in claim 8 further including a cleaning housinghaving a cleaning region therein and containing an opening thereinthrough which the surface of said drum is capable of being passed, saidcleaning housing having sidewalls which rotatably support said roll anda storage region remote from said cleaning region.

10. An apparatus as in claim 8 wherein said cleaning element comprisesan elastomeric blade biased into pressure contact with the surface ofsaid drum.

11. An apparatus as in claim 10 wherein, said blade element has acutting edge thereon whereby the cutting edge of the blade moves betweenthe residual toner material and the drum surface.

12. An apparatus as in claim 11 wherein, the length of said roll is atleast equal to that of said drum whereby the roll serves to seal aportion of the cleaning region so as to prevent the separated tonerparticles from escaping from the cleaning housing.

1. An apparatus for separating residual toner material from the surfaceof a reusable image retaining member preparatory to recycling saidmember, comprising: a cleaning element arranged to operativelycommunicate with said immage retaining member to separate residual tonerimages from the surface thereof; and sealing means positioned below saidcleaning element for intercepting the falling toner particles andtransporting said particles away from said reusable image retainingmember, said sealing means including a moving surface which is arrangedto ride in contact with said reusable image retaining member.
 2. Anapparatus as in claim 1 wherein said sealing means comprises a rollmounted for rotation.
 3. An apparatus as in claim 2 wherein, said rollhas an outer blanket thereon constructed of a resilient material.
 4. Anapparatus as in claim 3 wherein, said resilient material comprisesneoprene.
 5. An apparatus as in claim 3 wherein, said resilient materialhas a hardness of between about 50 and 60 durometers.
 6. An apparatus asin claim 3 further including a scraper bar adapted to ride in contactwith the outer surface of said sealing roll and arranged to separatesaid toner particles from said surface of said roll.
 7. An apparatus asin claim 6 wherein, said reusable image retaining member comprises axerographic drum.
 8. An apparatus as in claim 7 wherein, the contactingsurface of said drum and said roll move at the same relative speeds. 9.An apparatus as in claim 8 further including a cleaning housing having acleaning region therein and containing an opening therein through whichthe surface of said drum is capable of being passed, said cleaninghousing having sidewalls which rotatably supporT said roll and a storageregion remote from said cleaning region.
 10. An apparatus as in claim 8wherein said cleaning element comprises an elastomeric blade biased intopressure contact with the surface of said drum.
 11. An apparatus as inclaim 10 wherein, said blade element has a cutting edge thereon wherebythe cutting edge of the blade moves between the residual toner materialand the drum surface.
 12. An apparatus as in claim 11 wherein, thelength of said roll is at least equal to that of said drum whereby theroll serves to seal a portion of the cleaning region so as to preventthe separated toner particles from escaping from the cleaning housing.